def _VirtualFunctionCall(fname, f, pyname, abstract, postconvinit):
"""Generate virtual redirector call wrapper from AST.FuncDecl f."""
name = f.name.cpp_name
ret = astutils.FuncReturnType(f, true_cpp_type=True)
arg = astutils.FuncParamStr(f, 'a', true_cpp_type=True)
mod = ['']
if f.cpp_const_method: mod.append('const')
if f.cpp_noexcept: mod.append('noexcept')
yield ''
yield I + '%s %s%s%s override {' % (ret, fname, arg, ' '.join(mod))
params = astutils.TupleStr(
'std::move(a%i)' % i
for i in range(len(f.params) + len(f.returns) - (ret != 'void')))
yield I + I + 'SafeAttr impl(self(), "%s");' % f.name.native
yield I + I + 'if (impl.get()) {'
ret_st = 'return ' if ret != 'void' else ''
yield I + I + I + '%s::clif::callback::Func<%s>(impl.get(), {%s})%s;' % (
ret_st, ', '.join([ret] + list(astutils.Type(a) for a in f.params) +
list(astutils.FuncReturns(f))), ', '.join(
postconvinit(a.type) for a in f.params), params)
yield I + I + '} else {'
if abstract:
# This is only called from C++. Since f has no info if it is pure virtual,
# we can't always generate the call, so we always fail in an abstract class.
yield I + I + I + (
'Py_FatalError("@virtual method %s.%s has no Python '
'implementation.");' % (pyname, f.name.native))
# In Python 2 Py_FatalError is not marked __attribute__((__noreturn__)),
# so to avoid -Wreturn-type warning add extra abort(). It does not hurt ;)
yield I + I + I + 'abort();'
else:
yield I + I + I + ret_st + name + params + ';'
yield I + I + '}'
yield I + '}'
def FunctionCall(pyname,
wrapper,
doc,
catch,
call,
postcall_init,
typepostconversion,
func_ast,
lineno,
prepend_self=None):
"""Generate PyCFunction wrapper from AST.FuncDecl func_ast.
Args:
pyname: str - Python function name (may be special: ends with @)
wrapper: str - generated function name
doc: str - C++ sinature
catch: bool - catch C++ exceptions
call: str | [str] - C++ command(s) to call the wrapped function
(without "(params);" part).
postcall_init: str - C++ command; to (re)set ret0.
typepostconversion: dict(pytype, index) to convert to pytype
func_ast: AST.FuncDecl protobuf
lineno: int - .clif line number where func_ast defined
prepend_self: AST.Param - Use self as 1st parameter.
Yields:
Source code for wrapped function.
Raises:
ValueError: for non-supported default arguments
"""
ctxmgr = pyname.endswith('@')
if ctxmgr:
ctxmgr = pyname
assert ctxmgr in ('__enter__@',
'__exit__@'), ('Invalid context manager name ' +
pyname)
pyname = pyname.rstrip('@')
nret = len(func_ast.returns)
return_type = astutils.FuncReturnType(
func_ast) # Can't use cpp_exact_type.
# return_type mangled to FQN and drop &, sadly it also drop const.
void_return_type = 'void' == return_type
# Has extra func parameters for output values.
xouts = nret > (0 if void_return_type else 1)
params = [] # C++ parameter names.
nargs = len(func_ast.params)
yield ''
if func_ast.classmethod:
yield '// @classmethod ' + doc
arg0 = 'cls' # Extra protection that generated code does not use 'self'.
else:
yield '// ' + doc
arg0 = 'self'
yield 'static PyObject* %s(PyObject* %s%s) {' % (
wrapper, arg0, ', PyObject* args, PyObject* kw' if nargs else '')
if prepend_self:
yield I + _CreateInputParameter(pyname + ' line %d' % lineno,
prepend_self, 'arg0', params)
yield I + 'if (!Clif_PyObjAs(self, &arg0)) return nullptr;'
minargs = sum(1 for p in func_ast.params if not p.default_value)
if nargs:
yield I + 'PyObject* a[%d]%s;' % (nargs,
'' if minargs == nargs else '{}')
yield I + 'char* names[] = {'
for p in func_ast.params:
yield I + I + I + 'C("%s"),' % p.name.native
yield I + I + I + 'nullptr'
yield I + '};'
yield I + (
'if (!PyArg_ParseTupleAndKeywords(args, kw, "%s:%s", names, %s)) '
'return nullptr;' %
('O' * nargs if minargs == nargs else 'O' * minargs + '|' + 'O' *
(nargs - minargs), pyname, ', '.join('&a[%d]' % i
for i in range(nargs))))
if minargs < nargs and not xouts:
yield I + 'int nargs; // Find how many args actually passed in.'
yield I + 'for (nargs = %d; nargs > %d; --nargs) {' % (nargs,
minargs)
yield I + I + 'if (a[nargs-1] != nullptr) break;'
yield I + '}'
# Convert input parameters from Python.
for i, p in enumerate(func_ast.params):
n = i + 1
arg = 'arg%d' % n
yield I + _CreateInputParameter(pyname + ' line %d' % lineno, p,
arg, params)
cvt = (
'if (!Clif_PyObjAs(a[{i}], &{cvar}{postconv})) return ArgError'
'("{func_name}", names[{i}], "{ctype}", a[{i}]);').format(
i=i,
cvar=arg,
func_name=pyname,
ctype=astutils.Type(p),
# Add post conversion parameter for std::function.
postconv='' if p.type.cpp_type else ', {%s}' % ', '.join(
postconv.Initializer(t.type, typepostconversion)
for t in p.type.callable.params))
if i < minargs:
# Non-default parameter.
yield I + cvt
else:
if xouts:
_I = '' # pylint: disable=invalid-name
else:
_I = I # pylint: disable=invalid-name
yield I + 'if (nargs > %d) {' % i
# Check if we're passed kw args, skipping some default C++ args.
# In this case we must substitute missed default args with default_value
if (p.default_value ==
'default' # Matcher could not find the default.
or 'inf' in p.default_value): # W/A for b/29437257
if xouts:
raise ValueError(
"Can't supply the default for C++ function"
' argument. Drop =default in def %s(%s).' %
(pyname, p.name.native))
if n < nargs:
yield I + I + (
'if (!a[{i}]) return DefaultArgMissedError('
'"{}", names[{i}]);'.format(pyname, i=i))
yield I + I + cvt
elif (p.default_value and params[-1].startswith('&')
and p.type.cpp_raw_pointer):
# Special case for a pointer to an integral type param (like int*).
raise ValueError(
'A default for integral type pointer argument is '
' not supported. Drop =default in def %s(%s).' %
(pyname, p.name.native))
else:
# C-cast takes care of the case where |arg| is an enum value, while
# the matcher would return an integral literal. Using static_cast
# would be ideal, but its argument should be an expression, which a
# struct value like {1, 2, 3} is not.
yield _I + I + 'if (!a[%d]) %s = (%s)%s;' % (
i, arg, astutils.Type(p), p.default_value)
yield _I + I + 'else ' + cvt
if not xouts:
yield I + '}'
# Create input parameters for extra return values.
for n, p in enumerate(func_ast.returns):
if n or void_return_type:
yield I + '%s ret%d{};' % (astutils.Type(p), n)
params.append('&ret%d' % n)
yield I + '// Call actual C++ method.'
if isinstance(call, list):
for s in call[:-1]:
yield I + s
call = call[-1]
if not func_ast.py_keep_gil:
if nargs:
yield I + 'Py_INCREF(args);'
yield I + 'Py_XINCREF(kw);'
yield I + 'PyThreadState* _save;'
yield I + 'Py_UNBLOCK_THREADS'
optional_ret0 = False
if (minargs < nargs or catch) and not void_return_type:
if func_ast.returns[0].type.cpp_has_def_ctor:
yield I + return_type + ' ret0;'
else:
# Using optional<> requires T be have T(x) and T::op=(x) available.
# While we need only t=x, implementing it will be a pain we skip for now.
yield I + '::gtl::optional<%s> ret0;' % return_type
optional_ret0 = True
if catch:
for s in _GenExceptionTry():
yield s
if minargs < nargs and not xouts:
if not void_return_type:
call = 'ret0 = ' + call
yield I + 'switch (nargs) {'
for n in range(minargs, nargs + 1):
yield I + 'case %d:' % n
yield I + I + '%s; break;' % (call + astutils.TupleStr(params[:n]))
yield I + '}'
else:
call += astutils.TupleStr(params)
_I = I if catch else '' # pylint: disable=invalid-name
if void_return_type:
yield _I + I + call + ';'
elif catch:
yield _I + I + 'ret0 = ' + call + ';'
else:
yield _I + I + return_type + ' ret0 = ' + call + ';'
if catch:
for s in _GenExceptionCatch():
yield s
if postcall_init:
if void_return_type:
yield I + postcall_init
else:
yield I + 'ret0' + postcall_init
if not func_ast.py_keep_gil:
yield I + 'Py_BLOCK_THREADS'
if nargs:
yield I + 'Py_DECREF(args);'
yield I + 'Py_XDECREF(kw);'
if catch:
for s in _GenExceptionRaise():
yield s
if func_ast.postproc == '->self':
func_ast.postproc = ''
return_self = True
assert nret == 0, '-> self must have no other output parameters'
else:
return_self = False
# If ctxmgr, force return self on enter, None on exit.
if nret > 1 or (func_ast.postproc or ctxmgr) and nret:
yield I + '// Convert return values to Python.'
yield I + 'PyObject* p, * result_tuple = PyTuple_New(%d);' % nret
yield I + 'if (result_tuple == nullptr) return nullptr;'
for i in range(nret):
yield I + 'if ((p=Clif_PyObjFrom(std::move(ret%d), %s)) == nullptr) {' % (
i,
postconv.Initializer(func_ast.returns[i].type,
typepostconversion))
yield I + I + 'Py_DECREF(result_tuple);'
yield I + I + 'return nullptr;'
yield I + '}'
yield I + 'PyTuple_SET_ITEM(result_tuple, %d, p);' % i
if func_ast.postproc:
yield I + 'PyObject* pyproc = ImportFQName("%s");' % func_ast.postproc
yield I + 'if (pyproc == nullptr) {'
yield I + I + 'Py_DECREF(result_tuple);'
yield I + I + 'return nullptr;'
yield I + '}'
yield I + 'p = PyObject_CallObject(pyproc, result_tuple);'
yield I + 'Py_DECREF(pyproc);'
yield I + 'Py_CLEAR(result_tuple);'
if ctxmgr:
yield I + 'if (p == nullptr) return nullptr;'
yield I + 'Py_DECREF(p); // Not needed by the context manager.'
else:
yield I + 'result_tuple = p;'
if ctxmgr == '__enter__@':
yield I + 'Py_XDECREF(result_tuple);'
yield I + 'Py_INCREF(self);'
yield I + 'return self;'
elif ctxmgr == '__exit__@':
yield I + 'Py_XDECREF(result_tuple);'
yield I + 'Py_RETURN_NONE;'
else:
yield I + 'return result_tuple;'
elif nret:
yield I + 'return Clif_PyObjFrom(std::move(ret0%s), %s);' % (
('.value()' if optional_ret0 else ''),
postconv.Initializer(func_ast.returns[0].type, typepostconversion))
elif return_self or ctxmgr == '__enter__@':
yield I + 'Py_INCREF(self);'
yield I + 'return self;'
else:
yield I + 'Py_RETURN_NONE;'
yield '}'
